Apparatus and process for condensing a band of parallel continuous filaments



March 21, 1961 .1. c. WHITMORE 2,975,501

APPARATUS AND PROCESS FUR CONDENSING A BAND OF PARALLEL CONTINUOUS FILAMENTS Filed April 27, 1955 Fig. 1

INVENTOR JOHN C. WHITMORE BY @M ATTORNEY 'rower band or bundle.

APPARATUS AND PROCESS FOR CONDENSING A BAND F PARALLEL CONTINUGUS FILA- MENTS Filed Apr. 27, 1955, Ser. No. '5li4,193

Claims. (CI. 28-11 This invention relates to treatment of running filament bundles, particularly bands of essentially parallel continuous filaments, to condense or converge them widthwise during their lengthwise travel.

A well-known system of processing textile filaments into staple involves successive steps of drawing the filaments, arranged parallel to one another in band form, to increased length by passage over a series of rolls driven at appropriate speed differentials and then forcing or stufling the filaments by a pair of feeding rolls into a narrow confined channel in which they fold into an accordion-like configuration'or crimp. Construction of crimping mechanism suitable for this purpose is described by Hitt in Patent 2,311,174; as is readily apparent, uniformity of crimping is enhanced by presenting the filaments to the crimper as a non-varying bundle just wide enough to enter and fill the narrow passage provided. As the filament band leaving the drawing rolls customarily is considerably wider than the feeding rolls and the channel of the crimping mechanism, some way must be provided in between to convert the filaments into a nar- Conventionally, convergence is accomplished by passage between guides having the desired separation, which may be the flanges of a pulley or simply edges fixed in location; this produces maximum distortion of the filament bundle at the edges, with reduced likelihood of uniformity in subsequent treatment. Nonuniforrnity has been a particular problem in the convergence of filament bands to less than about one-fifth the original width, especially when the original Width exceeded about ten inches.

A primary object of the present invention is improved condensation of a band of filaments into a uniform narrow bundle. Another object is improved crimping of textile filaments. Other objects of this invention, together with means and methods for attaining the various objects, will be apparent from the following description and the accompanying diagrams.

Figure l is a side elevation of apparatus of this invention. Figure 2 is a plan view of the apparatus of Figure 1. Figure 3 is a side elevation of crimping mechanism including apparatus of this invention.

According to the present invention, condensation of a band of filaments to decreased width is accomplished by passing the band from a delivery roll through the nip of a pair of rolls whose line of mutual contact is centered with respect to the line of tangency of the band leaving the delivery roll but is oriented at an acute angle with respect to a projection of the line of tangency in a plane containing the axes of the pair of rolls and, thus, the line of mutual contact, the condensation accomplished thereby (i.e., ratio of initial to final band widths) being generally proportional to the secant of this intervening angle. The invention comprehends combination of a stulfing type of crimping mechanism having a pair of feed rolls rotatable about horizontal axes and, spaced thereabove, at least one delivery roll rotatable about a horizontal axis and oritates Patent 0 ented at an acute azimuthal angle with respect to the axes of the crimper feed rolls with its delivery edge centered vertically over the center of the nip line of the feed rolls and terminating at each end substantially directly above opposite sides of the feed rolls. The details of apparatus constructed according to this invention will be more apparent upon reference to the diagrams.

Figure 1 shows in side elevation band 1 of filaments passing from supply roll 2 over delivery roll 3 and down into the nip of rolls 4 and 4', which are located directly underneath. The same elements appear .in plan view in Figure 2, in which 0 indicates the angle between the line of contact of the pair of rolls and the line of tangency of the filament band with the delivery roll. The angle in the illustration, which otherwise is intended only as a general indication, is about corresponding to a condensation of about four times These first two drawings do not show any crimping mechanism as, of course, condensation may be accomplished for other purposes besides feeding a crimper. The path of the filament band between delivery roll and the subsequent rolls is preferably vertical, as shown, to eliminate any sidewise influence of gravity on the band. A pair of delivery rolls may be substituted for the single roll shown in Figures 1 and 2, if desired;

Figure 3 shows filament band 5 passing in open width through the nip of a pair of delivery rolls 6 and 6 to become converging band 7 on the way to feed rolls 8 and S, which stuff the converged band in accordion fashion as crimped bundle 9 inside the confined passage provided by crimper housing It Omitted from this and the other diagrams for simplicity are the axles and other supporting elements for the various rolls, which can be visualized without difiiculty.

Condensationof a filament band according to thepresent invention is more than mere convengence as accomplished by conventional guide means; it amounts to a uniform compacting of the band throughout its entire Width as each filament seeks the shortest path from delivery roll to feed roll. Any subsequent treatment of the condensed bundle, whether crimping, application of finish, or other, thereby is improved in uniformity. The desired degree of condensation will depend upon what the subsequent treatment is to be, and the azimuthal angle between delivery and feed rolls can be adjusted accordingly. Incondensation of a filament band for crimping by stuffing, the angle preferably is adjusted so that the converged band occupies substantially the entire width of the rolls feeding the crimper passage, as shown in the diagrams.

The present invention satisfactorily solves the previously existing problem of uniformly converging bands exceeding 10 inches in width to widths of /5 or less that amount. For example, for a sixfold condensation, as has been found desirable in crimping a band of 12 inches original width, composed of 144,000 nylon filaments each of 3 denier, the apparatus described above is employed with the intervening angle approximately Improvement in uniformity over previous methods is marked also even at somewhat lower condensation ratios.

As is readily apparent, although the original band width at the delivery roll and the width of the followingpair of rolls impose a limit upon the maximum azimuthal differential (i.e., the band should not project beyond the side edges of those rolls), there is no minimum limit. At high condensation it is desirable to maintain greater separation of the following or feed rolls from the delivery roll(s) to promote evenness of convergence; in general, satisfactory results will accompany such separation equal to or greater than the condensation ratio times the original half width of the band. Under some circumstances, as where very high condensation is desired or the original band width is variable, it may be desirable to accomplish the condensationinmore than one stage, which can be done easily by adding additional rolls (suitably oriented as taught herein) below what otherwise would have been the terminal set of rolls. Other adaptations and advantages of this invention will come readily to the mind Without necessity for the exercise of inventive faculties.

The claimed invention:

1.- Process comprising condensing a uniform band of essentially parallel continuous filaments from an original Widthto reduced Width by passing the filament band from a delivery roll through the nip of a pair of rolls Whose line of mutual contact is centered with respect to the line of tangency. of the band leaving the delivery roll but is oriented at an acute angle with respect to a projection of the line of tangency in a plane containing the taxes of the pair of rolls and, thus, the line of mutual contact, while maintaining the density of the filament band uniform throughout the condensation.

2. The process of claim 1 in which the ratio of original width to reduced Width approximates the seoant of the angle between the line of tangency and the line of mutual contact.

3. The process of claim 1 in which the original width is at least 10 inches and the ratio of original width to reduced Width is at least 5 to 1.

4. Apparatus for condensing a uniform band of essentially parallel filaments to reduced width while maintaining uniform densitythroughout the band comprising a mechanism having a pair of feed rolls rotatable about horizontal axes and, spaced thereabove, at least one delivery roll. rotatable about a horizontal axis oriented at an. acute azimuthal angle with respect to the axes of the feed rolls and with its delivery edge centered vertically over the center of the nip line of the feed rolls and terminating at each end substantially directly above opposite side edges of the feed rolls, the axial length of said feed rolls being less than that of any delivery roll, said appa ratus further comprising feed means for directly the band of filaments into tangential contact with said delivery roll and into the center of said feed rolls whereby the width of the band of filaments is reduced.

5. Process for condensing a band offilaments from an original width to a reduced width comprising providing (1 a delivery-roll for a uniform band of essentially parallel continuous filaments, and (2) a pair of rolls in mutual contact with one another, said band of filaments being in tangential contact with the delivery roll; arranging the pair of rolls so that the line of mutual contact of the pair of rolls is (a) centered with respect to the line of tangency of the band tothe delivery. roll, and (b) oriented at an acute azimuthal angle with respect to a projection of the line of tangency in a plane containing the axes of the pair of rolls and, thus, the line of mutual contact; uniformly condensing said band of filamentsfrom its original width to a reduced width while maintaining the density of the band uniformly throughout the condensation by passing the band of filaments from said delivery roll through the nip of the pair of rolls, the ratio of original width to reduced Width approximating the value of the secant of the angle between the line of tangency of the band to-the delivery roll and the line of mutual contact of the pair of rolls.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION It is hereby cert ent requiring correcti corrected below'.

ified that error appears in the above numbered paton and that the said Letters Patent should read as Column 4, line 3, for "directly" directing Signed and sealed this 25th day of July 1961.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer DAVID L. LADD Commissioner of Pat 

